Std::filesystem::path::string,std::filesystem::path::wstring,std::filesystem::path::u8string,std::filesystem::path::u16string,std::filesystem::path::u32string (3) Linux Manual Page

std::filesystem::path::string,std::filesystem::path::wstring,std::filesystem::path::u8string,std::filesystem::path::u16string,std::filesystem::path::u32string – std::filesystem::path::string,std::filesystem::path::wstring,std::filesystem::path::u8string,std::filesystem::path::u16string,std::filesystem::path::u32string

Synopsis

template <class CharT, class Traits = std::char_traits<CharT>,

          class Alloc = std::allocator<CharT>>
(1)(since C++ 17)

    std::basic_string<CharT, Traits, Alloc>

    string(const Alloc &a = Alloc()) const;

std::string string() const;

std::wstring wstring() const;

std::u16string u16string() const;

std::u32string u32string() const;
(2)(since C++ 17)

    std::string u8string() const;
(since C++ 17)(3)(until C++ 20)

    std::u8string u8string() const;
(since C++ 20)

Returns the internal pathname in native pathname format, converted to specific string type. Conversion, if any, is performed as follows:
* If path::value_type is char, conversion, if any, is system-dependent. This is the case on typical POSIX systems (such as Linux), where native encoding is UTF-8 and string() performs no conversion.
* Otherwise, if path::value_type is wchar_t, conversion, if any, is unspecified. This is the case on Windows, where wchar_t is 16 bit and the native encoding is UTF-16.
* Otherwise, if path::value_type is char16_t, native encoding is UTF-16 and the conversion method is unspecified.
* Otherwise, if path::value_type is char32_t, native encoding is UTF-32 and the conversion method is unspecified.
* Otherwise, if path::value_type is char8_t, native encoding is UTF-8 and the conversion method is unspecified.
1) All memory allocations are performed by a.
3) The result encoding in the case of u8string() is always UTF-8.

Parameters

(none)

Return value

The internal pathname in native pathname format, converted to specified string type.

Exceptions

(none)

Example

// Run this code

#include <cstdio>

#ifdef _MSC_VER

#include <io.h>

#include <fcntl.h>

#else

#include <locale>

#include <clocale>

#endif

#include <fstream>

#include <iostream>

#include <filesystem>

namespace fs = std::filesystem;
int main()

{

#ifdef _MSC_VER
    _setmode(_fileno(stderr), _O_WTEXT);

#else
    std::setlocale(LC_ALL, "");
    std::locale::global(std::locale(""));
    std::cout.imbue(std::locale());
    std::wcerr.imbue(std::locale());

#endif
    fs::path p = fs::u8path(u8"要らない.txt");
    std::ofstream(p) << "File contents"; // Prior to LWG2676 uses operator string_type()
                                         // on MSVC, where string_type is wstring, only
                                         // works due to non-standard extension.
                                         // Post-LWG2676 uses new fstream constructors
                                         // native string representation can be used with OS APIs
    if (std::FILE *f =

#ifdef _MSC_VER
            _wfopen(p.c_str(), L"r")

#else
            std::fopen(p.c_str(), "r")

#endif
    ) {
        int ch;
        while ((ch = fgetc(f)) != EOF)
            putchar(ch);
        std::fclose(f);
    }
    // multibyte and wide representation can be used for output
    std::cout << "\nFile name in narrow multibyte encoding: " << p.string() << '\n';
    std::wcerr << "File name in wide encoding: " << p.wstring() << '\n';
    fs::remove(p);
}

Output:

  File contents
  File name in narrow multibyte encoding: 要らない.txt
  File name in wide encoding: 要らない.txt

std::filesystem::path::string,std::filesystem::path::wstring,std::filesystem::path::u8string,std::filesystem::path::u16string,std::filesystem::path::u32string (3) Linux Manual Page